For employment verification, you must use a third party service located at www.theworknumber.com 

To contact Expedia's corporate headquarters;

Expedia Corporate Office
3150 139th Ave. SE
Bellevue, WA 98005 USA
Corporate Phone Number: 1-425-679-7200
Corporate Fax Number: 1-425-702-2722
Corporate Email: [email protected]

Do not expect a quick response using Email.